UK METAL DETECTING

austin · Joined: 30 Jun 2007 Posts: 65

In all the tech discussions I've read about NiMh cells, one thing often stressed is the importance of the cells not getting too hot during charging/topping up - as this will radically shorten their life. Also deep-cycling them is apparently bad for life expectancy. Small frequent top-ups seem a good way to go. Google it for tech articles.

I just replaced my existing Uniross 4xAA charger (mains plug built into the lump) with a 12v input Uniross X-PRESS 1000, which charges MUCH cooler. The old one would heat up the cells so they were uncomfortable to hold (I'm guessing perhaps 50 Celsius). The new one never makes them hotter than very warm (30 Celsius?). The difference is huge, and should keep my NiMhs going. The X-PRESS also has electronic voltage sensing, so cells can be topped up until full without getting roasted.

The X-PRESS cost me about £15 on eBay with 4x 2000 AA cells, and comes with a mains adapter and car cig. lighter adapter. Separating the mains adapter from the battery holder keeps things cooler anyway, as the mains transformer usually adds its own heat to that of the cells.

Austin Smile

dave123 · Joined: 29 Jul 2007 Posts: 24 Location: brightlingsea

Good morning Austin

I have had problems with battery charges in the past (overheating). This time I have brought an Energiser Ultra compact charger with an automatic switch off facility it came with 4 AA 2500 mAh, and 2 AAA batteries. It cost, I think it was £24 at Argos. Seems to work okay.
I wish I'd read this post earlier it might have saved me a couple of Bob Lol

m3ens · Joined: 03 Feb 2008 Posts: 3 Location: north shields

im sorry to say that all rechargeble batts get hot when charged its because of the chemical process that go on in side of them, when you chrarge them,and it does not degrade tham at all, if it does there cheap enough to get new one £5,99 2000ma AA how much does a set of 4 duracell cost 2,99? so if you even get 10 charges and then put them in the bin your saving money